Sync-n-link and Carb rebuild

[Jason]

Sure hope I did it right. It's all new to me!

All in pursuit of figuring out why she won't run over 4K. I actually did the sync n link a week ago with no positive results. So figures it would be worth cleaning out the carbs then doing another sync n link. Actually pretty simple to do once you get the darn things out of there! I'd like to have a few words with Mr. Kiekhaefer. Carb's actually were not bad but one of the filters was half clogged with gunk. I'll have to find some open water this weekend to see if it helped any.

[David CVX-16]

Somehow your engine looks familiar to me. Way to dig into the engine Jason. Did you get carb rebuild kits? Clean the parts in the distributor - all contact points, change the carbon contact in the middle that is spring loaded.You had mentioned that the fuel system was also leaking. I would change fuel line, bulb, and end fittings. Sometimes the fuel pickup from the gas tank can also be faulty. The bulb should be hard when you squeeze it. Also change fuel diaphrams.  Have you used Mercury "Power Tune" sprayed through the carbs and into the combustion chambers?  Also Sea Foam in the fuel tanks.  Let us know the outcome of your testing. Willing to get on White Bear Lake in the afternoon again.  

We might switch over to my gas tank and fuel line to eliminate that as the problem. I also have extra fuel diaphams and check valves. Mercury switched types of fuel diaphams over the years so may not be compatable.

[wiliermdb]

Did a little searching on the web about your issue and I came across two articles where a reed plate was the cause of the same issue you're having. One of the articles stated that the owner could feel air coming out of one of the carbs instead of sucking in and it was one broken reed on the plate.

Thought this may help. Hope you can get it up and running. Frustrating.

[Hyperacme]

What Dave said ...
And check for bad wires.
Knowen problem on old Merc's.

[Jason]

I have not torn into the distributor yet. I can tell it has never been opened up as it still has the little warranty locks on the nuts from new.

I did look at one of the fuel pumps and it looked OK but those are fairly cheap and are next in line.

That fuel line that was leaking quit leaking so I was not so worried about it at the moment. The fuel system is holding pressure from the bulb.

I was also thinking reeds..... I was going to leave that as the very last option. Can you get those out without ripping the entire block apart? I suppose I van just feel at the carbs and see if it's blowing out like you were saying.

Thanks for the help guys. I'll keep you posted.

[David CVX-16]

The inside of the distributor can be very dirty and greasy. Clean everything inside including the light sensors. I used a Dermel wire brush attached to a drill to clean all the contacts. I assume the right spark plugs are being used - Champion L76 or L78, or NKG BUHW.

The one to ask about reeds is Steve Acherman.

[Jason]

Ran it today with no better results.

Pulled the cap off for the first time in 44 years. Was pretty nasty, greasy, and corroded. Could easily see it missing from that. Cleaned them off good and out for a day on the river tomorrow. Hope it does the trick.

I put in new plugs a couple weeks ago too. Champ L76.

Original plug wires too. Those may be causing some problems.

[wiliermdb]

I would change the wire set just to get new wires on there. After that many years it's worth changing them. That's what I did with my '77 model Evinrude 115 that came on my CVX. New plugs, wires, coils, carbs cleaned, timing checked and set, new fuel lines and water pump. This way I know that it's all new and gives some peace in mind.

[Rosscoe]

Looks like a pain working on the carbs. Way to tear in. You'll get it figured out. Unreal...the distributor had never been opened up.

[Hyperacme]

http://www.maxrules.com/timingindex.html

http://www.maxrules.com/carbindex.html

[David CVX-16]

Jason, the spark plug wires are rarely the problem. Merc did a good job with the original set. If it were the wires, the motor would be missing. If you do decide to switch wires, you have to buy lengths of wire and fabricate both ends. They no longer sell them ready to install. I went through this several years ago and was told that unless there was a problem, do not switch, and I did not.

[Jason]

Was on the Mississippi about 7 hours today. Ran better than ever but still turning low RPM's. It missed a little before but after cleaning the dist cap that went away. Had 4 of us in the boat today and maxed out at about 3500RPM's and 25MPH. I am starting to think it is just to much boat for that engine. I am just gonna keep my eye out for a 140 or 150 merc and do a switcheroo. The wife is happy with the slower speeds. It's what she wanted after all.

Mississippi is still at least 4-5 feet higher than it should be. The current was really strong. Some places were like rapids. But still a lot of fun and without any problems so it was a good day!

[Rich_V174SS]

I thought all this time your engine was a 115. I doubt it's too much boat for that engine, you should still get another 10-15 mph out of it and 5000 rpm unless the engine is just tired. I don't remember if you've done a compression check and what results you had.

[Jason]

Compression was 135-140 on all cylinders. If a reed were bad wouldn't that affect compression?

[Rich_V174SS]

Compression seems good. A bad reed might affect compression but you'd get blow-back out of the carb. What size prop are you running again? I'm thinking a 17p should be on there but no smaller than a 15p.

With my '83 Merc 115 on the V176 Swinger I'm spinning a 19p stainless and getting 5600 rpm at 47 mph.

* Just re-read your prop testing post. If there's no difference in rpm between the 15 and 17 pitch props I would keep looking into fuel delivery. Is there a point in the throttle before WOT where rpm stops increasing? At that point and above does it sound like the engine is leaning out?

Another test I like to do is while the engine is running at say mid throttle is pull each spark plug wire one at a time to see if there's a change in sound. Pull a wire, listen for a difference, put the wire back on. If you get no change on a cylinder (or pair of cylinders) then that will narrow down where you need to concentrate on the problem.

[Jason]

The RPM and power increase feels pretty gradual as it should from closed to WOT. You can feel where the distributer stops turning and the last bit where the butterflys open on the carbs. It really does not seem to be missing either. Runs pretty smooth for an outboard but i think that might be a good test to try anyway. I am not gonna blow up my control box by pulling plug wires am I? I think Steve (74carlson) has a test light that connects to all cylinders so you can see all of them firing. I might just need to take it up to him sometime as he is the local power of tower expert!

[dorelse]

I think that's a good idea Jason.  (Bring a camera, take some spy shots of the CV-19OB.)

[Rich_V174SS]

The spark test is not just to test spark but also tests to see if you're getting fuel and combustion at each piston. No change in running attitude when a plug is pulled can tell you. You'll know if you're getting spark because it will arc with the boot pulled, you may even get zapped so be careful and insulate yourself.

[Jason]

I've done that on cars a few times. Grabbed a wire once with a big crack in it! Biggest shock of my life. Forced my opposite arm to punch the wall behind me!